Set back thermostat-Best models and do they equals savings ?
Posted on February 26, 2020
What is a set back thermostat ?
A set back thermostat is basic type of non programmable thermostat that does not have programming feature. Instead the temperature set point can be altered only through manual operation. Traditionally they were mechanically operating only but now most modern thermostat come with electronic control.
These thermostats are inexpensive alternative to contemporary programmable or smart thermostats.
It is also suitable for people who have irregular schedule so require quite a lot of manual intervention.
What does set back mean ?
Set back in temperature is the change in set point of temperature to allow the heating or cooling device to res or in other words run at lower load or not run at all.Basically the furnace or your ac etc will run only when the temperature falls below or rises above your setback temperature.
This will allow the system to use less energy and results in savings.
Set back Types
Basically there are two types of setbacks-
When the home is vacant-In this type you lower the load of your hvac equipment when no one is at home and so will not feel uncomfortable.
When sleeping at night-At night you can lower the heating or cooling as night temperatures are lower than day so you don’t need that much heating or cooling.This is called night-setback.
Does set back thermostat save energy bills?
There are debates around whether setback result in saving or not.
Well according to physics it should. Any degree of setback no matter how small it is will save you money.
The amount you can save will depend on your commitment to save and also how well insulated your home is as well as the type of system you are using. A slow acting system will result in less saving while a well insulated home will also save more money.
Relation between setback time duration and saving
Well US department of energy says that 1 degree of setback for 8 hours results can result in 1 % of energy saving.Well this may vary according to your system and insulation of home.The most important factor is your commitment to save energy and thus have regular setbacks for the long run whenever you are not at home or asleep at night.
Here is a simple chart of setback temperature and proposed energy savings.
|Time||6am to 9pm||9pm to 6am||Proposed Saving|
|Winter||68°F (20°C)||58(14°C)||11 % (6°C/8hrs *15 hrs)|
|Summer||78°F (26°C)||96(36°C)||18 % (10°C/8hrs *15 hrs)|
Switch back to normal time
Well you should also look into the time it requires for your system to bring the house back to your comfortable temperature and thus adjust you normal time in advance. You don’t need to bother with this in Smart thermostat with smart recovery feature like in Honeywell but with non programmable set back thermostat you need to keep that into account.
Setback and humidity
How much you should set back the temperature not only depends on the outside temperature but also on the humidity levels. You should find a best set point so that Relative humidity of house is in comfortable range.
In winter the RH may increases at night causing condensation at windows walls etc.
In summer too If your Ac doesn’t run less than required there may be rise in humidity causing moisture issues like molds etc in the house.
Set back with heat pumps
If you have heat pump you can save energy efficiently only in cooling mode when using setback. In heating mode a heat pump uses back up electric resistance heat system to heat back to normal temperature and set back will cause the heat pump it to operate inefficiently. A moderate setbacks will give you optimum saving. Few companies make thermostats with algorithms to minimize use of backup electric heat system. With such thermostat you can have much more setbacks and thus savings.
Best set back or non programmable thermostats
If you are looking for a non programmable thermostat chances are you have an old traditional furnace or cooling system or you have a irregular schedule so you don’t want to rely on programmable or smart thermostats.
There are basically three type of thermostats
Line voltage-120 to 240 V
When looking for non programmable thermostats check if its compatible with your system. In following we have listed more thermostats compatible with most of the systems or listed separately that are just for single system like Line voltage thermostats.
Honeywell RTH111B1016/E1 Digital Non-Programmable Thermostat
This is the cheapest low voltage thermostat you can get. Know that it is snot compatible with electric baseboard heating as it do not support 120 or 240 line voltage. It has excellent feedback on amazon. Some of its features customers liked are its easy set and precise temperature control. It keeps the set point on power outage as it operates on 2 AA batteries too. Overall its a best value for your money if you don’t require anything fancy or cumbersome.
Emerson 1F83C-11NP Conventional (1H/1C) Non-Programmable Thermostat
Emerson company provides automation and engineering services for wide range of industrial and home applications. It also manufactures some of the best smart thermostats. While above thermostat is a non programmable design of Emerson it has some advance feature like screen lockout to prevent unauthorized access and also temperature limits within which your HVAC equipment will perform. A large display and easy set up and precise control are also its recognizable features. It is also compatible with multiple type of system including of up to 1 heating and cooling stages, heat pumps and millivolt system with 3 wire zone valves.
Lux Products DMH110 Non-Programmable Digital Thermostat
This is a basic model of lux which manufacturers adjustable differential thermostats. This thermostat is also a adjusting differential type thermostat with +- 3 differentials.It is compatible with sigle stage Gas, Oil, Electric or sigle stage heat pumps and also millivolt systems.Easy installation and temperature is switchable to Celcius and Fahrenheit. If you have a short cycling problem and want a handy inexpensive thermostat this one is definitely for you.The setback is achieved by save button which allows to alter setpoints.
PRO1 IAQ T771 Heat or Cool Only Electronic Thermostat
Pro1 also makes adjustable differential thermostats. The temperature differential on this thermostat is from 0.2 to 2 degree F. The power supply can be battery or line voltage. Most people find it to be excellent replacement for their garage or RV owner and want to run in low temp but prevent temperature going below freezing. When working you can turn it up again to comfortable temperature. They find it to be better than Honeywell which has a lower set point of 35 degree F while this has lower set point of 25 degree F.
Honeywell RLV3120A1005/E1 Digital Non-Programmable Thermostat
This thermostat is designed only for electric baseboard heating only. It is a line voltage thermostat with both 120 and 240 V line compatibility. No batteries are required and set point is retained in memory. Compact design allows easy installation. You can display temperature in Celsius and Fahrenheit. The temperature control is accurate (0.15 degree) and a on screen heating power indicator. It is also cheap when compared to other baseboard heater thermostats of Honeywell or other companies.
Honeywell Manual 4 Wire Premium Baseboard/Line Volt Thermostat
This is another baseboard type thermostat with mechanical control. Both 120 and 240 V compatible and very easy to install. It can control up to to 5,2800W with 2 or 4 wire non polarized connections. This works on most basic type bimetallic temperature sensor that actively senses temperature and can be bought for just 17 bucks on amazon and has impressive ratings and feedback.